Preheat the oven to 180°C/350°F/Gas Mark 4. Grease a 30cm x 22.5cm/12 x 9 inch oven tray/flat baking tray and dust with flour.

To prepare the base, cream the butter and sugar together in a mixing bowl. Work in the flour with a wooden spoon or electric mixer. Press into the baking tray and bake for 15 to 20 minutes or until shortbread base is golden in colour. Remove from the oven and leave to cool.

To prepare the filling, put all the ingredients in a pan and heat gently until the sugar has dissolved, stirring occasionally. Increase the heat and, taking care not to burn, boil the mixture slowly for 5 minutes, stirring continuously. Remove from the heat, leave to cool for 1 minute, then pour onto the cooled shortbread base. Leave to set.

Melt the chocolate in a small heatproof bowl over a pan of hot water. Spread over the set filling. Mark into portions, fingers or squares, and leave until quite cold and set before removing from the baking tray.

Makes 18-20.

Preheat oven to 160°C/325°F/Gas Mark 3 and position rack in the centre of the oven.  Prepare a 22.5 cm/9 inch round cake tin by lining the bottom and sides with baking paper and brushing lightly with oil. Melt the chocolate in a small heatproof bowl over a pan of hot water.  Allow to cool slightly. Sift the flour, baking powder, baking soda, and salt together in a bowl and set aside until ready to use.

In a large mixing bowl, cream butter, then add sugar, almond flavouring and cocoa powder with an electric mixer until well blended.  The appearance will be grainy and lumpy. Gradually add eggs, one at a time, mixing until each is incorporated into the mixture.  Add melted chocolate to creamed mixture and blend it in so that the batter is smooth.

Heat the milk with the water until hot to touch (not boiling).  Set aside. Add the dry ingredients to the mixing bowl with the butter, sugar, chocolate mixture. Slowly fold in, then mix until completely blended. With your electric mixer on slow, pour in the hot milk and water. Increase the speed to medium to completely mix everything together. If it is too stiff, add water a tablespoon at a time to get a soft but not loose cake batter consistency.

Pour the batter into the prepared cake tin and place in the preheated oven for 40 minutes, or until a wooden toothpick inserted into the centre comes out clean.  Allow to cool completely before removing it from the cake tin.  Once cooled, wrap the cake with plastic wrap and place in the fridge until completely chilled (about 1½ hours).

While the cake is cooling, prepare the chocolate mousse. Melt the chocolate and butter together in a small heatproof bowl over a pan of hot water. When the mixture is completely smooth and glossy, scrape into a large bowl and set aside.

In a clean bowl, mix the heavy cream until it comes together and whip lines are slightly visible.  Place in the fridge to keep chilled.

Heat eggs, sugar, and water in a small heatproof bowl over a pan of hot water. Whip until frothy, and warm to the touch. Pour the mixture into a clean bowl and mix on high until the mixture is very thick, smooth, and nearly white in colour, about 8-12 minutes.

Scoop about ⅓ of the egg mixture into the melted chocolate and butter, and using a folding motion, lightly blend.  There will be streaks of light and dark in the mixture. Add the rest of the egg mixture to the chocolate, carefully folding until a fairly uniform tone. Lightly fold in whipped cream. Place the mousse in the fridge until it is solid and the cake is ready to assemble.

To assemble the cake, very lightly spray a 22.5 cm/9 inch springform tin with oil and line it with baking paper. Remove the cake from the refrigerator and using a very long, sharp knife, slowly slice through its middle to create two layers of equal size. (A serrated, sharp, bread-knife works well).

Carefully place one layer into the bottom of the springform tin making sure it is snug. Remove the mousse from the fridge and spread half of it over the cake layer, making sure to even it out to the edges. Add the second layer of cake and place it over the mousse.  Gently press.

Spread the remaining mousse over the second cake layer, spreading to smooth it out on top. Place the cake in the freezer for at least 4 hours. If you are making this one day in advance, once the top of the cake is firm to touch, cover it in plastic wrap.

While cake is chilling, prepare almond buttercream frosting. In a bowl, beat the heavy whipping cream until holds its shape in peaks, chill. In a separate clean bowl, cream softened butter, icing sugar, and almond flavouring until smooth. Combine the chilled cream into the almond buttercream mixture. Chill until ready to use (at least 1 ½ hours).

Once the cake and mousse layers are chilled, the cake is ready to be frosted. Prepare the cake plate you will serve the cake on by lining it with pieces of baking paper to be removed after icing. Remove the springform tin from the freezer. 

Run a thin knife smoothly around the edge of the pan to help release it.  Remove the cake from the tin and peel off the baking paper from its bottom. Place the cake on the prepared cake plate. Spread the top and sides thinly with the chilled almond buttercream frosting. Place in the refrigerator while the chocolate ganache and decoration are prepared.

To make the ganache topping, heat the heavy cream, corn syrup, and palm shortening in a pan until just below boiling.  Stir to blend, then pour the mixture over the chopped chocolate. Allow to sit for two minutes, then mix well until everything is smooth and glossy. Add the almond flavouring and stir well.

To use immediately, remove the cake from the refrigerator, pour the ganache over the surface of the cake and with an offset spatula, quickly smooth across the surface of the cake, allowing some to dribble down the sides. Place the cake back in the refrigerator.

If making the ganache ahead of time, place in the refrigerator in a covered container.  When ready to use, heat in a microwave to bring to a pourable consistency and proceed as described above.

To prepare the toasted almond decoration, place almond slivers in a heavy, ungreased skillet. Stir continuously over medium heat until golden brown. Cool for 30-40 minutes.

Remove the cake and put the toasted almond slivers along the edge of the finished cake, pressing in gently.  This decoration gives the cake a delightful finish and elegant, nutty flavour.

Notes

It is suggested that, for best results, this cake is made a day prior to serving, otherwise, allow at least six hours to make and assemble cake. Make sure the cake has ample time, at least 30 minutes, in the refrigerator to thaw before serving. Use a warm knife to slice through.

Serves 16-20.